Smartphone displays are becoming larger than ever. But there’s a limit to how big a device can get before it can’t fit in your pocket anymore. One way manufacturers are trying to get around that is to fold a screen in half.

Seven years after Samsung first revealed it’s working on a foldable smartphone, the company finally unveiled its widely anticipated device this week. It works like a tiny book: The front cover features a regular screen, and the entire handset folds out to reveal a tablet-sized display.

Samsung is calling the technology Infinity Flex Display. It runs the One UI -- an Android variant optimized for bendable usage, created in collaboration with Google. Samsung says its device will enter mass production in the coming months.

But Samsung isn’t the first to introduce a foldable smartphone.

ZTE, for example, launched the Axon M handset early this year that also folds like a book. Unlike Samsung’s bendable display though, the Axon M features two separate 5.2-inch screens -- with a black seam sitting glaringly in the middle.

Then last week, a little-known Chinese company called Royole created a bit of a storm when it showed off a flexible phablet that bends like a blanket -- though it looked like the software was still pretty buggy.

Lenovo also teased a bendy prototype a few weeks earlier. 

Patent filings have revealed yet more possible designs from other phone makers. Huawei’s sketch, for instance, shows a device that also folds together like a book -- while Apple’s submission points to a device that rolls together like an ancient scroll.

Of course, patents don’t always lead to products. Tech companies often apply for patents just to secure the rights to a design, regardless of whether they’ll bring the feature to the market. But with Samsung’s latest entry, it shouldn’t be a surprise to see more manufacturers jumping on the bendable bandwagon.